DB_SORT

COMMAND TYPE : UTILITY

PURPOSE:

To sort an existing catalogue with respect to a field.

DESCRIPTION:

With this command the user can sort a given catalogue with respect to a field. When a catalogue is sorted the sort code is updated in the system files and some DIRA commands can work in a more efficient way.

This command execute an ASCII sort of the required field using the sort command supplied by the operative system. The ASCII sort is not equivalent to a numerical sort when there are negative numbers or when the + sign is not in a defined column in the field. When the user want to sort a catalogue on the coordinates the use of the first coordinate that, usually, has positive values only is suggested.

INPUT FIELDS of the command:

From: PDB ?

The user must enter Y when the input catalogue is in Personal Data Base.

Example : Y

Catalogue Name

The name of the input catalogue to sort.

Example : UGC

Field:

The name of the field that will be used as sort key.

Example : RADVEL

Output: File Name

The name of the output sorted file.

Example : SORTCAT.DAT

PDB Catalogue Name

The name of the new catalogue in the Personal Data Base. When this field is filled an entry in the PDB for this new catalogue will be created and the user can continue to work on these new data with DIRA. Otherwise only the output file will be written. Valid catalogue names are strings of 12 or less characters that do not contain any special symbols.

Example : SORTCAT

NOTE:

This task writes a file that has the same size of the input file.



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